The conventional razor is known to have the construction in which a guard located below and in front of the cutting edge is made to move independently of the razor blade so as to vary the shaving angle and the contacting angle.
Since in the conventional razor, the razor blade is adapted to move relative to the guard, the span (the distance between the guard and the cutting edge) and therefore the shaving angle (the angle between the horizontal level and the line connecting the guard top surface and the cutting edge) may vary while cutting whiskers. This is a disadvantage in that it will result in trembling of the cutting edge, especially when the span is long, subjecting the skin of the operator to pain.
Another disadvantage is that, because of the relative movement between the guard and the razor blade, they cannot always be kept parallel to each other and the cutting quality of the conventional razor is not stable.